Cancer in cats

Skin tumours can be common in cats, and can be benign or cancerous. If you notice any unusual lumps or bumps on your cat's skin, always contact your vet.

Many tumours in the skin are benign and can be surgically removed. If the lump is very large or in a difficult area, there are occasions when removing the tumour can be tricky. This is something your vet will be able to discuss with you.

There are also some types of skin tumours that can come back, and a few that can spread to other areas in the body. If this is the case, your vet may cut out a larger area of skin during surgery, to reduce the risk of the tumour returning or spreading further.

Cats have four breasts on each side of their tummy, and tumours can be found in one or more at a time. Unfortunately, these tumours are often cancerous.

If your cat has a breast tumour, your vet is likely to recommend surgery to remove all of the breast tissue on the affected side. This helps to prevent further lumps from growing on that side, which is often the case if only the lump alone is removed.

If the tumour is cancerous, surgery may not stop the spread of cancer internally. It is common for this cancer to spread to the lungs, so chest imaging before surgery are often advised, although it is not always possible to detect early spread.

Leukaemia or lymphoma is a type of cancer that affects white blood cells called lymphocytes. Lymphocytes are a part of your cat's immune system and travel through their blood and a network called the lymphatic system. This is made up of lymph nodes (also known as glands), which help your cat's body screen for infections and harmful substances.

When lymphocytes become cancerous, they start growing uncontrollably. They can increase in your cat's blood or group together in one place, making a lump. This can cause your cat's lymph nodes to become enlarged in areas such as their neck.

The cancerous lymphocytes can also spread to other parts of your cat's body and can affect their liver, spleen, or bowel.

As lymphoma travels around your cat's body, surgery alone is not usually advised. While the average life expectancy from diagnosis is around two months, this can be prolonged with chemotherapy. But unfortunately, not all lymphomas respond – especially if your cat has FeLV.

Your vet will be able to advise the treatment best for your cat.

For an isolated tumour that has not spread, surgery may provide a cure, but it is not always necessary if the tumour is benign and is not causing discomfort.

Surgery is often chosen for tumours of the skin, or for internal tumours that can be easily located. If the tumour is cancerous, it will need to be analysed once removed, to find out whether the cancer is likely to have spread. Sometimes, with large internal tumours, surgery can relieve your cat's symptoms, but there is a risk that it will return.

For tumours in certain parts of the body, surgery can be very difficult, or even impossible. While it may be possible to remove a tumour in a hard to access area like the brain for example, this is a specialist procedure which can be very costly.

Chemotherapy can be used for several types of cancer. Veterinary chemotherapy usually has little side effects, because the doses used are smaller than those used in humans. Unfortunately, it does not usually cure cancer – the aim is to slow the cancer down and reduce the symptoms.

Chemotherapy is sometimes carried out following surgery if it has not been possible to remove the entire tumour. This is to try to slow down the chance of it spreading. It is also used for cancers that cannot be surgically removed, such as those involving the white blood cells (leukaemia).

How chemotherapy is given

Some types of chemotherapy may be available from your own vet, but others are only carried out by specialists. It involves regular visits to the vet, where your cat will often have to be sedated. You may also be asked to give your cat tablets.

While there are few side effects, chemotherapy can cause a short period of reduced appetite, vomiting or diarrhoea. Sometimes it can also cause your cat's white blood cell count to drop, which increases their risk of infection. Your vet will usually take blood tests to check for this during the treatment.

Radiotherapy is only available at a few specialist centres, and like chemotherapy, it does not usually cure the cancer. This type of treatment uses radiation to target and kill cancer cells.

Regular visits to the specialist centre are often needed for a period of time while your cat is undergoing radiotherapy. Your cat will need to be absolutely still for the treatment, so a short general anaesthetic will be given for each treatment.